Below is a short introduction to the languages spoken on myaasia:

There are 5 native base tongues, these are really not spoken by anyone, bust some scholars can read the and even fewer people talk.

Old Elven(Qualia)
Dark Tongue(Uruk)
Old Tongue(Higar)
Stonespeak
High Dragonic

Most(about 95%) of the actual tongues are some derivate of those 5 (Think of Latin as the base tongue and French,Spanish,Italian,Portugese etc. as the actual active languages)

The relationships for some common tongues:
all these have many dialects, and some of the dialects are far enough that two speakers of the supposedly same language could have difficulty of understanding each other.

(the elven tongues)
High elven(Iylar) (dialects of this are spoken by the Iylari clans) about a third of all magic texts are written in this language.
Erlini(The woodelven tongue of most of myaasia, though most of these are quite different languages when spoken to other members of the same clan, they tend to have a common core and when speaking to other people there is usaully a “common” erlini)
Danya (Spoken by the 1000 islands elves, some consider it a very strange dialect of Erlin instead and it is possible to usually communicate with a speaker of erlini.)
Fetimar(The elven tongue of the elves in the south myaasian jungles. Some groups of elves living there are so isolated that their language is very different from erlini)
Sulini(The language of most elves and halfelves and many others in Govon and the boat nomads)
Myri(Than language of the Myri people)
High Drow(The language of old that many drow used to speak, and most can still atleast read it slowly, Most drow speak the erlini based dialects in their daily use, usually calling them “drow”)

(the mannish tongues)
Ivak (the language of a group of wizardly folks, long dead, but the language lives on as about magic books are still written in this langauge)
Logar(the language of the central kingdom of myaasia)
Common(a bastardised tradetongue very close to logar, cannot really be used to express anything too complex)
Abirai (the language of the orginal inhabitants of the eastern myaasia, the fisherpeople, and the language spoken by most native humans in 1000 isles)
Rohim(the language of the rohim)

(the orcish tongues)
High orcish (The northern empire court language)
East Orcish (Spoken by the orcs in eastern myaasia and 1000 isles)
North Orcish (Spoken by the orcs in north empire)
Sagath (the language of the sagath tribes)
Aslak (The language of most humans living in north)
Duranaki(The language of the people of duru)
Urukian (“The uruk common” spoken by most orcs and such as a trade tongue)

K'jart (The Dwarves of northeast of myaasia and the 1000 isles speak mostly this tongue)
Gnomish(Remarkably most gnomes anywhere seem to speak this tongue, though some dialects are a bit hard to understand. About a tenth of all magic text are written in this tongue)
Hilly(The halfling and hill dwarf language of the really east part of myaasia and the 1000 isles)
High Duegar(The languare of the duegar nobles, old fashoned language that tends to be similar everywhere, though people seldom actually use it)

Each of the 12 dragonlords that used to be had a own tongue that the dragons spoke, usually in the forms of a “high tongue” “normal tongue” and “low tongue” and many others.
So on 1000 isles:
Skytongue(Dragonlord court language, used mostly in ceremonies, close to old dragonic)
Ferder (Common draconic spoken by most dragonians and such, a bastardised and much simplified version on skytongue)
Gesterti (The most common lizardman tongue on the islands)
Drog (The language spoken by the drogs)
other geographical places will ofcourse have other tongues

Other planes have their own languages ofcourse, but again most such places seem to have a “common” thus most firecreatures know atleast a bit of “fire common” and so on..

Most people would know their own langauge, maybe some neighbouring language and common.
Most wizards would also learn written Ivak and Iylar at some point.
Most elemental bloods would know the local langauge and the correct elemental tongue